Research & Sources

Every statistic on Lysco comes from official government sources, peer-reviewed research, or major nonpartisan organizations. We do not make claims we cannot cite.

Last verified: June 15, 2026

The statistics on our landing page

If you arrived here from the landing page, these are the six figures we cite. Tap any card to jump to the full primary-source citation.

80%

of hospital bills reviewed contain at least one error — 4 in 5

MBAA / NerdWallet / OIG

99%+

of denied Marketplace claims were never appealed

KFF, 2024

95%

of appealed Medicare Advantage skilled-nursing denials were overturned in a 2026 federal review

HHS OIG, 2026

1.2 sec

average review time as one major insurer’s system denied 300,000+ claims

ProPublica

$1,300

average total billing error on hospital bills over $10,000

NerdWallet / OIG

$220B

estimated U.S. medical debt

KFF, 2022

Insurance Denials & Appeals

Just 5% of in-network ACA Marketplace denials cite "lack of medical necessity" — the remaining 95% are paperwork, administrative codes, missing referrals, or coverage exclusions

KFF—Claims Denials and Appeals in ACA Marketplace Plans, 2024 — full breakdown: 36% "Other" (unspecified), 25% Administrative, 16% Excluded service, 9% Lack of prior authorization or referral, 5% Medical necessity, plus smaller categories.

19% of in-network ACA Marketplace claims were denied in 2024 — tied with 2023 for the highest rate since the Marketplaces launched

KFF—Claims Denials and Appeals in ACA Marketplace Plans, 2024 — out-of-network denial rate: 37%. Denial rates ranged from 3% to 36% across insurers in HealthCare.gov states.

Approximately 85 million in-network claims were denied on HealthCare.gov in 2024 (out of ~451 million processed)

KFF—Marketplace Plan Transparency Data Analysis, 2024 — derived from the 19% in-network denial rate applied to total claim volume.

Fewer than 1% (≈0.31%) of denied in-network ACA Marketplace claims are appealed — across documented plan types, more than 99% of denials are never appealed

KFF—262,982 internal appeals against ~85 million in-network denials in 2024. Insurers upheld 66% of internal appeals (overturning ~34%). Combined with Medicare Advantage (11.5% of 4.1 million prior-auth denials appealed), the volume-weighted never-appealed rate across documented segments is ~99.2% — the landing's "99%" rounds down.

~81% of appealed Medicare Advantage prior-authorization denials are fully or partially overturned (2024)

KFF—Medicare Advantage Insurers Made Nearly 53 Million Prior Authorization Determinations, 2024 — refined to 80.7%. Centene's overturn rate after appeal reaches ~96%.

75% of Medicare Advantage care denials are overturned when fully reviewed

HHS Office of Inspector General (OIG)—Medicare Advantage Appeal Outcomes audit, 2022 — sample-based study using a conservative "overturned" definition. Cross-checks the higher 2024 KFF figure.

95% of appealed Medicare Advantage skilled-nursing-facility admission denials were overturned in a 2026 federal review

HHS Office of Inspector General (OIG)—HHS OIG reviewed June 2024 skilled-nursing-facility admission requests. The 19 Medicare Advantage organizations denied 12% of requests; enrollees and providers appealed 18% of denials; plans overturned 95% in favor of the enrollee. NaviHealth-issued denials were overturned 97% when appealed.

Only 11.5% of Medicare Advantage prior-authorization denials are appealed

KFF—Medicare Advantage prior-authorization data, 2024 reporting cycle. 4.1 million MA prior-auth denials in 2024 (7.7% denial rate, up from 5.7% in 2019).

13% of denied MA prior-authorization requests met Medicare coverage rules and should have been approved

HHS Office of Inspector General (OIG)—Prior Authorization and Payment Denials in Medicare Advantage, 2022 — denials that did not align with Medicare coverage criteria.

External-review overturn rates run 50–80% in patients' favor when patients fight back

CA DMHC, MD Insurance Admin, CT OHA, PA Insurance Dept—California IMR: ~73% in patient's favor (DMHC 2024 Annual Report). Maryland: 64% reversal. Connecticut Office of the Healthcare Advocate: ~80%. Pennsylvania external review: ~50%. NY DFS external appeals: 42% fully + 2% partially overturned (2023).

Only 40% of US consumers know they have a legal right to appeal externally

KFF—Survey of Consumer Experiences with Health Insurance, 2023 — 51% are unsure; 9% don't believe they have appeal rights. Marketplace enrollees are least aware (34%).

66% of insured adults call insurance delays and denials a "major problem" — and 33% had a service or medication denied in the past two years

KFF—KFF health tracking polling, January 2026. Spans employer, Marketplace, Medicare, and Medicaid coverage.

States have begun outlawing AI as the sole basis for a claim denial — Arizona, Maryland, Nebraska, and Texas have enacted limits

State insurance statutes, 2024–2026—Enacted in response to insurer claim-automation revelations, including reporting that one major insurer's review system denied 300,000+ claims at an average of 1.2 seconds of physician review each — now the subject of active litigation.

94% of physicians say prior authorization delays access to necessary care

American Medical Association (AMA)—2024 Prior Authorization Physician Survey of 1,000 physicians. 93% say PA negatively impacts patient outcomes; 89% say it drives burnout; 24–29% report PA led to a serious adverse event for a patient.

Physicians complete an average of 39 prior-authorization requests per week; staff spend 13 hours/week on them

American Medical Association (AMA)—2024 Prior Authorization Physician Survey. 40% of physicians employ staff working exclusively on PAs; 82% say PA leads patients to abandon recommended treatment.

73% of healthcare finance leaders say claim denials are increasing across payers

Experian Health—Experian 2024 State of Claims Survey — up from 42% in 2022. 41% of providers report denial rates ≥10%. Initial denial rates hit 11.81% in 2024 (Crowe RCA Benchmarking).

US hospitals spend an estimated $19.7 billion per year managing denied claims

Premier Inc.—Premier 2024 Trend Alert on payer denial costs. Premier also reports >54% of initially denied private-payer claims are ultimately paid after appeal.

Cigna doctors denied over 300,000 requests for payment using an algorithmic review process, averaging 1.2 seconds per case

ProPublica (March 2023, Marshall Allen)—Investigation into Cigna's PXDX system. Findings were repeated verbatim in California and Connecticut federal class-action complaints filed in 2023.

UnitedHealthcare's skilled-nursing-facility denial rate increased ninefold (9x) from 2019 to 2022, coinciding with the deployment of an internal AI tool (nH Predict)

US Senate Permanent Subcommittee on Investigations—Refusal of Recovery: How Medicare Advantage Insurers Have Denied Patients Access to Post-Acute Care, October 2024. Report focused on UnitedHealth's NaviHealth subsidiary.

Medicare Advantage processed 53 million prior-authorization determinations in 2024

KFF—Up from 49.8 million in 2023. 4.1 million denials at a 7.7% denial rate. By insurer: UnitedHealthcare 12.8%; Centene 12.3%; Aetna 11.9%; Kaiser 10.9%; Humana 5.8%; Elevance 4.2%.

CMS 2026 rule: 72-hour urgent / 7-calendar-day standard prior-authorization decisions required

Centers for Medicare & Medicaid Services (CMS)—CMS Interoperability and Prior Authorization Final Rule (CMS-0057-F). Applies to MA, Medicaid, CHIP, and Marketplace plans. Drug PA rule (CMS-0062-P) effective Oct 2027.

Medical Debt & Consumer Protections

Americans owe an estimated $220 billion in medical debt

KFF analysis of the Survey of Income and Program Participation (SIPP)—KFF, 2022. Debt distribution is highly skewed: ~14 million Americans owe more than $1,000; ~3 million owe more than $10,000. Nearly 1 in 5 don't expect to pay it off in their lifetime.

100 million Americans carry medical or dental debt

KFF/NPR—Health Care Debt Survey, 2022 — broader definition (includes past-due bills, balances being paid off over time, medical credit cards, and personal loans for healthcare). Roughly 41% of US adults.

36% of US households carried medical debt in 2024 — roughly $194 billion estimated in active collections

JAMA (analysis of two nationally representative 2024 surveys)—21% of households had a past-due medical bill and 23% were paying one off over time. Complements KFF's broader $220B total-owed estimate and CFPB's narrower credit-report figure — each measures a different slice of the same problem.

About two-thirds of US consumer bankruptcies (~66.5%) cite medical bills as a contributor

Himmelstein et al., American Journal of Public Health—Medical Bankruptcy: Still Common Despite the Affordable Care Act, 2019 — 65.5% pre-ACA / 67.5% post-ACA. Broad-definition study (any household with >$1,000 in medical bills, mortgaging a home for medical bills, or losing 2+ weeks of work to illness). More conservative definitions place medical-cause bankruptcies in the 20–60% range.

31 million Americans borrowed an estimated $74 billion in 2024 to pay for healthcare

West Health-Gallup Healthcare Survey—Fielded November 11–18, 2024 (n=3,583); published March 5, 2025. 11% of US adults are classified as "Cost Desperate" — unable to afford or access quality care.

63% of US adults could not cover an unexpected $400 expense entirely with cash or equivalent

Federal Reserve — Survey of Household Economics and Decisionmaking (SHED), 2024—Roughly 30% could not cover three months of expenses by any means. 26% of US adults skipped some form of medical treatment in 2025 because they could not afford it.

Approximately 50% of US adults could not pay an unexpected $500 medical bill without borrowing

KFF—Health Care Debt Survey and follow-up reporting. Of those, 19% could not pay it at all; 5% would have to borrow from a bank, payday lender, or family; 21% would put it on a credit card and carry the balance.

About $88 billion in medical debt collections appeared on US consumer credit reports as of mid-2021

Consumer Financial Protection Bureau (CFPB)—Medical Debt Burden in the United States, March 2022. CFPB's broader medical-debt credit-reporting rule was vacated in July 2025. The three major bureaus' separate 2023 policy removing collections under $500 remains in effect.

Roughly 1 in 5 US hospitals have denied non-emergency care to patients with unpaid bills

KFF Health News — "Diagnosis: Debt"—Investigative series, 2022–2024. Many additional hospitals retain formal policies allowing the practice even when not actively enforced. Some hospitals also push patients toward medical credit cards charging up to 29% interest.

Around 250,000 medical fundraising campaigns are launched on GoFundMe per year

GoFundMe / NORC at the University of Chicago—GoFundMe's then-CEO Rob Solomon told CBS MoneyWatch in January 2019 that "one-third of all donations on GoFundMe goes towards health care costs." A peer-reviewed study of 437,596 medical campaigns (2016–2020) found only 12% met their funding goal in 2020.

61.8% of people who negotiated a problematic medical bill reported a lower price

JAMA Health Forum—Disparate Patient Advocacy When Facing Unaffordable and Problematic Medical Bills, 2024.

Nonprofit hospitals are required to maintain financial assistance policies (501(r))

Internal Revenue Service (IRS)—Section 501(r) Requirements for Charitable Hospitals — requires policies to be widely publicized and limits how much can be charged to patients eligible for assistance.

Medical Bills, Errors & Negotiation

Estimates of medical-bill error rates range from 49% to 80%

Medical Billing Advocates of America (MBAA) / OIG hospital audits—Pat Palmer of MBAA reports ~80% of hospital bills reviewed contain at least one error. NerdWallet Health's 2014 analysis of OIG Medicare hospital compliance audits across 34 hospitals found 49% of claims contained errors, with overpayments averaging 26% above actual costs. Equifax's dollar-volume figure is lower (~13%).

Average errors on $10,000+ hospital bills total roughly $1,300

NerdWallet Health—October 2014 analysis of CMS OIG hospital compliance audits.

Average emergency-department visit total cost: $2,453; out-of-pocket for large-employer coverage averages $646

Peterson-KFF Health System Tracker—Cost analysis of ED visits, 2024. Appendicitis ED visits run ~$9,535 total ($1,717 out-of-pocket). Uninsured patients pay roughly $2,600 on average per visit.

HIPAA §164.524 gives patients the right to request an itemized bill from any provider

US Department of Health and Human Services (HHS)—The HIPAA Privacy Rule grants individuals the right to access protected health information, including billing records, from covered entities. Patients can submit a written request and providers must respond within 30 days.

Contingency medical-bill negotiators and billing advocates keep 10–35% of whatever they save you

Consumer Reports / published service pricing—Consumer Reports: billing advocates working on contingency usually take 25–35% of savings (CoPatient charged 35%). Published service rates as of 2026: Goodbill charges 20% of savings capped at $1,000; Resolve charges a tiered 10–25% of savings plus an upfront deposit. Hourly advocates run ~$75–$150/hr.

Surprise Bills & No Surprises Act

1.4 million No Surprises Act IDR disputes were filed in 2024 — a 115% year-over-year increase

Georgetown Center on Health Insurance Reforms / Health Affairs—Providers win ~85% of IDR payment determinations, often at 3–4x the insurer's qualifying payment amount. Total IDR system administrative cost: ~$5 billion through 2024.

More than 10 million surprise medical bills were prevented in the first nine months of 2023

America's Health Insurance Plans (AHIP)—AHIP analysis of No Surprises Act protections in effect. CMS had received >16,000 NSA complaints by mid-2024 with $4M+ in restitution recovered.

A final bill that is $400+ over the Good Faith Estimate triggers Patient-Provider Dispute Resolution

Centers for Medicare & Medicaid Services (CMS)—No Surprises Act — Patient-Provider Dispute Resolution process. Available to self-pay and uninsured patients.

45% of insured adults received unexpected bills for services they believed were covered

KFF / American Journal of Managed Care—Survey on Billing Errors and Insurance Practices.

Cost-Related Care Avoidance

36% of US adults skipped or postponed care due to cost in the past 12 months

KFF Tracking Poll—2024 tracking poll. 75% of uninsured adults went without needed care. 37% of insured adults still skipped care due to cost. 18% of all adults said their health got worse because of skipped or delayed care.

43% of US adults did not take medication as prescribed because of cost

KFF—Including 27% who did not fill a prescription, 19% who cut pills in half, and others who skipped doses or substituted over-the-counter drugs.

Roughly 30% of people with a chronic illness skip doses, cut pills in half, or leave prescriptions unfilled due to cost

KFF—Includes about 25% of adults who had health insurance for the full year.

Healthcare Spending & Affordability

National health spending reached $5.3 trillion in 2024 (18.0% of GDP) — about $15,474 per person

Centers for Medicare & Medicaid Services (CMS)—National Health Expenditure Accounts, 2024. Hospital spending: $1.63T (+8.9%); physician services: $1.11T (+8.1%); prescription drugs: $467B (+7.9%).

US per-capita health spending is roughly 2x the wealthy-country OECD average

OECD / Peterson-KFF—~$14,885/person in 2024 vs. ~$7,371 OECD wealthy-country average. Switzerland is the next-highest at $9,963. The US spends >$1,000 per person on administrative costs alone, roughly 5x the OECD wealthy-country average.

Health spending is projected to reach 20.3% of GDP by 2033

CMS Office of the Actuary—National Health Expenditure Projections 2024–2033. Average annual growth of 5.6%, outpacing GDP growth of 4.3%. Medicare spending projected to grow 7.4%/year through 2032.

Average employer-sponsored family premium: $26,993 in 2025 (+6% YoY, +24% over five years)

KFF—2025 Employer Health Benefits Survey. Single coverage: $9,325. Workers contribute $6,850 toward family coverage on average. 34% of covered workers face a deductible ≥$2,000 (53% at small firms with 10–199 workers).

44% of adults say healthcare costs are difficult to afford

KFF—Health Care Costs Survey, 2024.

23% of working-age adults with year-round coverage are underinsured

The Commonwealth Fund—Biennial Health Insurance Survey, 2024. 66% of the underinsured have employer coverage. 57% reported avoiding care due to cost; 44% had medical debt.

Coverage & Medicaid

27.1 million Americans were uninsured in 2024 (8% of the population)

US Census Bureau—Current Population Survey and American Community Survey, 2024. Working-age (19–64) uninsured rate: 11.3%. The ACS-measured uninsured rate ticked up from 7.9% in 2023 — the first increase in years, driven mostly by Medicaid unwinding.

24.2 million Americans enrolled in ACA Marketplace coverage in 2025

CMS—More than double the 12 million enrolled in 2021, driven by enhanced premium tax credits.

Roughly 27 million people disenrolled from Medicaid after the post-pandemic unwinding

KFF / GAO—KFF Medicaid Enrollment and Unwinding Tracker. 69% of disenrollments were procedural (not eligibility-based).

If enhanced ACA premium tax credits expire, subsidized enrollees' premiums could rise 114% — from $888 to $1,904/year

KFF / CBO—KFF analysis, September 2025. CBO projects ~10 million more people uninsured by 2034 under the 2025 "One Big Beautiful Bill Act" plus subsidy expiration.

The subsidy cliff arrived: benchmark ACA premiums rose ~26% for 2026, and ~9% of 2025 enrollees were already uninsured by early 2026

KFF—Enhanced premium tax credits expired at the end of 2025. Average paid premiums rose ~58% as many enrollees bought down to higher-deductible plans; 55% of re-enrollees report cutting basic household spending to keep coverage.

Hispanic Americans face the highest uninsured rate at 24.6% among adults 18–64

KFF / National Health Interview Survey (NHIS)—2024 NHIS data — nearly four times the rate of non-Hispanic Whites (7.9%).

Healthcare Workforce & Access

92.3 million people live in primary-care shortage areas

Health Resources and Services Administration (HRSA)—Health Professional Shortage Area Statistics, January 2026.

137.1 million people live in mental-health shortage areas

HRSA—Mental Health HPSA Designations.

Projected 141,160 FTE physician shortfall by 2038

HRSA—Physician Workforce Projections, 2025.

Chronic Disease & Aging

76.4% of adults had at least one chronic condition (2023)

Centers for Disease Control and Prevention (CDC)—National Health Interview Survey, Chronic Condition Surveillance. 51.4% had multiple chronic conditions.

Over-65 population projected to reach 21% of total by 2040

Economic Report of the President, 2024—Chapter on Population and Aging.

Medicaid Long-Term Services and Supports: 9.7 million users; $228.6 billion in expenditures (2023)

CMS—Medicaid LTSS Annual Expenditures Report.

How we use these sources

Lysco uses published data to contextualize individual cases — for example, citing the national denial overturn rate when analyzing a user's specific denial. We do not guarantee that any individual case will match aggregate outcomes.

Outcome statistics on the Lysco platform (such as average savings per case) are based on aggregated, anonymized data from actual cases processed through the system and are updated regularly.

Citations are re-audited on a recurring basis. The June 15, 2026 date in the header reflects the most recent full pass through every source listed on this page.

Important caveats

Medical-bankruptcy figure: the widely cited 66.5% Himmelstein figure uses a broad definition (any household with >$1,000 in medical bills, mortgaging a home for medical bills, or 2+ weeks of lost work). More conservative academic definitions place medical-cause bankruptcies in the 20–60% range.
Bill-error rates: the 49–80% range spans rigorous and advocacy sources. The 49% figure is from NerdWallet Health's 2014 analysis of OIG hospital compliance audits. The 80%+ figure is reported by Medical Billing Advocates of America; Equifax's dollar-volume figure is lower (~13%).
Appeal overturn rates vary by jurisdiction: the 80.7% MA prior-auth overturn rate is well-documented (KFF 2024 / 2026). ACA Marketplace internal appeal overturn rate is much lower (~34%). State external-review overturn rates run 50–80% in most states with published data.
Self-funded ERISA plan transparency gap: public CMS Transparency in Coverage data covers ACA Marketplace plans. Self-funded employer plans (~60% of employer coverage) report claims-denial data to state regulators via NAIC MCAS, but most of that data is not public. The published denial picture may understate the full commercial market.
Future projections (CBO, CMS Office of the Actuary): assume current law. Legislation enacted after the verification date may change projected enrollment, premium, and uninsured figures.

If you believe any citation is incorrect or outdated, please contact us at research@lysco.com.

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